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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Electric heater in my combi boiler radiator circui https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1291115573 Message started by jonny1234 on Nov 30^th, 2010, 11:12am

Title: Electric heater in my combi boiler radiator circui
Post by jonny1234 on Nov 30^th, 2010, 11:12am

hi can i install an instantaneous water heater in line with my radiatir circuit in a combi boiler, i want to use electrc to warm my rads when gas is cut off or not avail plus i get cheaper elec with solar so would like to make most of it, can a normal in line heater be used and can it stand pressure, i will use boiler pump but put boiler temp low so pump works but boiler wont fire as elec heater will keep stat off with warm water?? i think

Title: Re: Electric heater in my combi boiler radiator circui
Post by big_all on Nov 30^th, 2010, 1:55pm

all your day to day non heating applications will use up most off your "free electricity"

on average on a sunny day you will only reach about 80% and above on average for a few hours a year
over the year the output is likley to be around 20 to 30 % off the suggested maximum

and when you need the heat you panels are at thee least efficant

don't forget if you use more than the panels produce you pay the full price for it

Title: Re: Electric heater in my combi boiler radiator circui
Post by CWatters on Nov 30^th, 2010, 3:41pm

How much solar PV are you considering?

I think the normal solution if you have an excess is to use any spare to run an immersion heater element in the hot water tank. Perhaps put a mixer on the hot output from the tank to reduce the temperature to a safe level. That way the tank can be operated over a wider temperature range and store more energy.

Quote:

i will use boiler pump but put boiler temp low so pump works but boiler wont fire as elec heater will keep stat off with warm water?

I guess the boiler might lock out eg water much hotter than the set temperature = fault?.

Might be better just to put the heater in parallel with the boiler and use a valve to select which one the pump sends the water through. Same switch that controls the valve can also steer the output from the room stat to either the electric heater or the boiler (might need a relay).

Title: Re: Electric heater in my combi boiler radiator circui
Post by thescruff on Dec 1^st, 2010, 2:59am

The easiest way would be to install a thermal store and run the radiators from that.

The combi can still heat the store through the coil, but you would need to separate the hot water with say the kitchen/utility connected to the combi.
To re-cap.

The store is heated via the immersion heater or boiler.

The hot water is mains pressure from the store, except the kitchen.

The heating is run from the store using a second pump and controls.

Title: Re: Electric heater in my combi boiler radiator circui
Post by Lucius Hohl on Aug 6^th, 2014, 8:54am

wrote on Nov 30^th, 2010, 11:12am:

hi can i install an instantaneous water heater in line with my radiatir circuit in a combi boiler, i want to use electrc to warm my rads when gas is cut off or not avail plus i get cheaper elec with solar panels so would like to make most of it, can a normal in line heater be used and can it stand pressure, i will use boiler pump but put boiler temp low so pump works but boiler wont fire as elec heater will keep stat off with warm water?? i think

hello friend bit old thread but which heater have you got? Even I am looking to add new heater so can you help me with your experience..

Title: Re: Electric heater in my combi boiler radiator circui
Post by thescruff on Aug 6^th, 2014, 9:41am

Hi and welcome to askthetrades.

I don't think information in the Uk will be of any use in Mumbai, Maharashra, or elsewhere in India.